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  • 【Hibernate 一对多】

    OneToMany

    public class OneToMany {
    
        @Test
        public void testAdd1() {
            SessionFactory sessionFactory = null;
            Session session = null;
            Transaction tx = null;
            try {
                sessionFactory = HibernateUtils.getSessionFactory();
                session = sessionFactory.openSession();
                tx = session.beginTransaction();
    
                Customer customer = new Customer();
                customer.setCustName("顾客1");
                customer.setCustLevel("vip");
                customer.setCustSource("网络");
                customer.setCustPhone("138");
                customer.setCustMobile("999");
    
                LinkMan linkman = new LinkMan();
                linkman.setLkm_name("联系人1");
                linkman.setLkm_gender("男");
                linkman.setLkm_phone("109");
    
                customer.getSetLinkMan().add(linkman);
                linkman.setCustomer(customer);
    
                session.save(customer);
                // session.save(linkman);
                tx.commit();
                System.out.println("====================");
            } catch (Exception e) {
                e.printStackTrace();
                tx.rollback();
            } finally {
                if (session != null)
                    session.close();
                if (sessionFactory != null)
                    sessionFactory.close();
            }
        }
    
        @Test
        public void testDelete1() {
            SessionFactory sessionFactory = null;
            Session session = null;
            Transaction tx = null;
            try {
                sessionFactory = HibernateUtils.getSessionFactory();
                session = sessionFactory.openSession();
                tx = session.beginTransaction();
    
                Customer customer = session.get(Customer.class, 1);
                if (null != customer) {
                    session.delete(customer);
                }
                tx.commit();
                System.out.println("====================");
            } catch (Exception e) {
                e.printStackTrace();
                tx.rollback();
            } finally {
                if (session != null)
                    session.close();
                if (sessionFactory != null)
                    sessionFactory.close();
            }
        }
    }

     Customer

    public class Customer {
        //客户id
        private Integer cid;
        //客户名称
        private String custName;
        //客户级别
        private String custLevel;
        //客户来源
        private String custSource;
        //联系电话
        private String custPhone;
        //手机
        private String custMobile;
    
        //在客户实体类里面表示多个联系人,一个客户有多个联系人
        //hibernate要求使用集合表示多的数据,使用set集合
        private Set<LinkMan> setLinkMan = new HashSet<LinkMan>();
    
        public Set<LinkMan> getSetLinkMan() {
            return setLinkMan;
        }
    
        public void setSetLinkMan(Set<LinkMan> setLinkMan) {
            this.setLinkMan = setLinkMan;
        }
    
        public Integer getCid() {
            return cid;
        }
    
        public void setCid(Integer cid) {
            this.cid = cid;
        }
    
        public String getCustName() {
            return custName;
        }
    
        public void setCustName(String custName) {
            this.custName = custName;
        }
    
        public String getCustLevel() {
            return custLevel;
        }
    
        public void setCustLevel(String custLevel) {
            this.custLevel = custLevel;
        }
    
        public String getCustSource() {
            return custSource;
        }
    
        public void setCustSource(String custSource) {
            this.custSource = custSource;
        }
    
        public String getCustPhone() {
            return custPhone;
        }
    
        public void setCustPhone(String custPhone) {
            this.custPhone = custPhone;
        }
    
        public String getCustMobile() {
            return custMobile;
        }
    
        public void setCustMobile(String custMobile) {
            this.custMobile = custMobile;
        }
    }
    View Code

    Customer.hbm.xml

    <?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE hibernate-mapping PUBLIC
            "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
            "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
    <hibernate-mapping>
        <!-- 1 配置类和表对应
            class标签
            name属性:实体类全路径
            table属性:数据库表名称
        -->
        <class name="k.entity.Customer" table="t_customer">
            <id name="cid" column="cid">
                <generator class="native"></generator>
            </id>
            <property name="custName" column="custName"></property>
            <property name="custLevel" column="custLevel"></property>
            <property name="custSource" column="custSource"></property>
            <property name="custPhone" column="custPhone"></property>
            <property name="custMobile" column="custMobile"></property>
    
            <!-- 在客户映射文件中,表示所有联系人
                使用set标签表示所有联系人
                set标签里面有name属性:
                     属性值写在客户实体类里面表示联系人的set集合名称
    
                 inverse属性默认值:false不放弃关系维护
                                true表示放弃关系维护
            -->
            <set name="setLinkMan" inverse="true" cascade="save-update,delete">
                <!-- 一对多建表,有外键
                    hibernate机制:双向维护外键,在一和多那一方都配置外键
                    column属性值:外键名称
                 -->
                <key column="clid"></key>
                <!-- 客户所有的联系人,class里面写联系人实体类全路径 -->
                <one-to-many class="k.entity.LinkMan"/>
            </set>
        </class>
    </hibernate-mapping>

    LinkMan

    public class LinkMan {
        private Integer lkm_id; // 联系人编号(主键)
        private String lkm_name;// 联系人姓名
        private String lkm_gender;// 联系人性别
        private String lkm_phone;// 联系人办公电话
    
        // 在联系人实体类里面表示所属客户,一个联系人只能属于一个客户
        private Customer customer;
        public Customer getCustomer() {
            return customer;
        }
        public void setCustomer(Customer customer) {
            this.customer = customer;
        }
    
        public Integer getLkm_id() {
            return lkm_id;
        }
        public void setLkm_id(Integer lkm_id) {
            this.lkm_id = lkm_id;
        }
        public String getLkm_name() {
            return lkm_name;
        }
        public void setLkm_name(String lkm_name) {
            this.lkm_name = lkm_name;
        }
        public String getLkm_gender() {
            return lkm_gender;
        }
        public void setLkm_gender(String lkm_gender) {
            this.lkm_gender = lkm_gender;
        }
        public String getLkm_phone() {
            return lkm_phone;
        }
        public void setLkm_phone(String lkm_phone) {
            this.lkm_phone = lkm_phone;
        }
    }
    View Code

    LinkMan.hbm.xml

    <?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE hibernate-mapping PUBLIC
            "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
            "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
    <hibernate-mapping>
        <!-- 1 配置类和表对应
            class标签
            name属性:实体类全路径
            table属性:数据库表名称
        -->
        <class name="k.entity.LinkMan" table="t_linkman">
            <id name="lkm_id" column="lkm_id">
                <generator class="native"></generator>
            </id>
            <property name="lkm_name" column="lkm_name"></property>
            <property name="lkm_gender" column="lkm_gender"></property>
            <property name="lkm_phone" column="lkm_phone"></property>
    
            <!-- 表示联系人所属客户
                name属性:因为在联系人实体类使用customer对象表示,写customer名称
                class属性:customer全路径
                column属性:外键名称
            -->
            <many-to-one name="customer" class="k.entity.Customer" column="clid"></many-to-one>
        </class>
    </hibernate-mapping>

    HibernateUtils

    public class HibernateUtils {
    
        static Configuration cfg = null;
        static SessionFactory sessionFactory = null;
        //静态代码块实现
        static {
            //加载核心配置文件
            cfg = new Configuration();
            cfg.configure();
            sessionFactory = cfg.buildSessionFactory();
        }
    
        //提供返回与本地线程帮的session的方法
        public static Session getSessionobject() {
            return sessionFactory.getCurrentSession();
        }
    
        //提供方法返回sessionFactory
        public static SessionFactory getSessionFactory() {
            return sessionFactory;
        }
    
        public static void main(String[] args) {
    
        }
    }

    hibernate.cfg.xml

    <?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
    <hibernate-configuration>
        <session-factory>
            <!-- 第一部分: 配置数据库信息 必须的 -->
            <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
            <property name="hibernate.connection.url">jdbc:mysql:///hibernate_day01</property>
            <property name="hibernate.connection.useUnicode">true</property>
            <property name="hibernate.connection.characterEncoding">UTF-8</property>
            <property name="hibernate.connection.username">root</property>
            <property name="hibernate.connection.password">root3306</property>
            
            <!-- 第二部分: 配置hibernate信息  可选的-->
            <!-- 输出底层sql语句 -->
            <property name="hibernate.show_sql">true</property>
            <!-- 输出底层sql语句格式 -->
            <property name="hibernate.format_sql">true</property>
            <!-- hibernate帮创建表,需要配置之后 
                update: 如果已经有表,更新,如果没有,创建
            -->
            <property name="hibernate.hbm2ddl.auto">update</property>
            <!-- 配置数据库方言
                在mysql里面实现分页 关键字 limit,只能使用mysql里面
                在oracle数据库,实现分页rownum
                让hibernate框架识别不同数据库的自己特有的语句
             -->
            <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
            
            <!-- 第三部分: 把映射文件放到核心配置文件中 必须的-->
            <!--<mapping resource="k/entity/User.hbm.xml"/>-->
            <mapping resource="k/entity/Customer.hbm.xml"/>
            <mapping resource="k/entity/LinkMan.hbm.xml"/>
        </session-factory>
    </hibernate-configuration>
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  • 原文地址:https://www.cnblogs.com/kikyoqiang/p/12292611.html
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